PROJECT SUMMARY The maintenance of a high level of skill is required of healthcare providers performing medical procedures to reduce patient suffering and decrease overall medical costs. Many studies of procedural skills have involved medical trainees and demonstrate the crucial need to change the way doctors are trained. More recently studies also have shown that attending physicians who have been practicing for years have a large variability in their procedural skills. Specifically, a recent study evaluated the ability of gastroenterologists (GI) doctors to remove polyps (polypectomy) from patients during routine colonoscopies for colon cancer screening, with a focus on assessing successful and complete polyp removal. Complete polyp removal is critical because polyps can turn into colon cancer over years. Study results demonstrated a wide variability in the skills of GI doctors in adequately removing polyps, which required some patients to undergo another colonoscopy, need to see another specialist, and resulted in increased procedure time?all of which can affect patient safety. Medical educators use simulation to increase trainees' essential knowledge and clinical skills. This approach assures competence without risk of patient harm. Simulation-Based Mastery Learning (SBML), a strict form of competency-based education, has repeatedly resulted in improved performance and patient care quality across a variety of clinical skills (e.g., putting in catheters into large central veins, draining fluid from the lungs). In SBML, each learner must demonstrate a high level of skill in the simulated setting before performing actual patient care. Mastery learning results in uniform learning outcomes with little variability and ensures that only competent personnel deliver patient care. The objective of this research project is to teach attending gastroenterologists using simulation technology and the mastery learning model with the aim of improving colon polyp removal skills and patient safety, and reducing healthcare costs. Our overall hypotheses are that SBML improves physician knowledge, promotes skill acquisition and retention, and improves clinical outcomes of polyp removal. Specific aims Aim 1: Develop a Simulation-based Mastery Learning (SBML) curriculum designed to improve polypectomy skills among gastroenterologists. Aim 2: Evaluate skill acquisition, skill retention, and need for retraining at six and 12 months among gastroenterologists completing the SBML polypectomy curriculum on both (a) simulator-based and (b) actual video-recorded patient polypectomies. Aim 3: Assess total procedure time, post-polypectomy site inspection, need for repeat colonoscopy, and hospital charges for patients receiving a polypectomy before and after the SBML training of gastroenterologists.